Open meteo example

[SandroMaglione]

This PR introduces a new real example of how to use fpdart.

The example comes from the bloc's package, specifically the Open Meteo API.

This example aims to show how to refactor imperative code to functional programming using fpdart. The example contains both the original code as well as the refactored code. The goal is to show a 1-1 comparison between the two solutions.

---

As part of this PR, also some new methods have been added to make the refactoring more effective:

• chainEither to TaskEither
• safeCast (Either and Option)
• safeCastStrict (Either and Option)

int intValue = 10;

/// Unhandled exception: type 'int' is not a subtype of type 'List<int>' in type cast
final waitWhat = intValue as List<int>;
final first = waitWhat.first;

/// Safe 🎯
final wellYeah = Either<String, List<int>>.safeCast(
  intValue,
  (dynamic value) => 'Not an List!',
);
final firstEither = wellYeah.map((list) => list.first);

[jacobaraujo7]

any news about this?

[SandroMaglione]

@jacobaraujo7 I am planning to complete the series of articles on the Open Meteo API (see part 1) before release, so that the example is released alongside a proper explanation.